• 제목/요약/키워드: air-water interface

검색결과 282건 처리시간 0.032초

상대운동을 하는 방제판 주위 물-기름-공기 유동 모사 (SIMULATION OF WATER-OIL-AIR FLOWS AROUND OIL BOOMS UNDER RELATIVE MOTION)

  • 신상묵
    • 한국전산유체공학회지
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    • 제21권3호
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    • pp.31-38
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    • 2016
  • The FDS-HCIB method is expanded to simulate water-oil-air flows around oil booms under relative motion, which is intended to increase the thickness of contained oil. The FDS scheme captures discontinuity in the density field and abrupt change of the tangential velocity across an interface without smearing. The HCIB method handles relative motions of thin oil booms with ease. To validate the developed FDS-HCIB code for water-oil-air flow around a moving body, the computed results are compared with the reported experimental results on the shape, length, and thickness of the oil slicks under towing. It is observed that the increase in pressure field between two barriers lifts the oil slick and the interfacial wave propagates and reflects as one barrier gets closer to the other barrier.

광학모델을 이용한 자외선 접촉조 최적 설계에 관한 연구 (A Study on Optimal Design of UV Contactor using an Optical Radiation Model)

  • 최영균;김두일;김성홍
    • 한국물환경학회지
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    • 제25권4호
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    • pp.547-552
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    • 2009
  • Because of refractory property of light, the travel path of UV light becomes longer than the straight line and shorter solely in water as UV light passes sequentially through air, quartz and water. Note that water significantly absorbs UV light. Hence, UV intensity shall be estimated to be lower when refraction is neglected than it is considered. Reflection is also critical for the design of UV radiation system. While the reflection at the interface of air and quartz is low enough to ignore, it is too high to be ignored at the interface of quartz and water. Assuming constant power, smaller length to width ratio of UV reactor is beneficial and single-lamp system is preferred to multi-lamps. Under the given cross section, optimal lamp positions could be decided. For example of an elliptical reactor with dual lamps, the optimal lamp locations shall be the 1/3 and 2/3 position of the longer axis.

고분자/금속화합물 LB막의 공기/물에서의 계면 특성 (Surface Characteristics of Polymer/Metal Compound LB Films in the Air/water Interface)

  • 신훈규;최용성;김은구;권영수;장정수;배진호;이범종
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1994년도 하계학술대회 논문집 C
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    • pp.1364-1366
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    • 1994
  • In this paper, the monolayers of the polymers which polyion-complexed with PAA at the air-water interrace can be transferred on to solid substrates such as porous fluorocarbon membranes filter and quartz crystal microbalance. The properties of the monolayers and the LB films investigated by ${\pi}-A$ isotherms, FT-IR, DSC, deposition ratio, QCM, and SEM will be discussed. In addition, it was attempted to investigated the surface characterics of polymer/metal compound LB films in the air/water interface.

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LBM을 이용한 Dam Breaking 수치해석 연구 (COMPUTATIONAL STUDY ON TWO DIMENSIONAL DAM BREAKING SIMULATION USING LATTICE BOLTZMANN METHOD)

  • 정노택;하산 엠디.캄롤
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2011년 춘계학술대회논문집
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    • pp.54-57
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    • 2011
  • In this paper we present an algorithm about how to simulate two dimensional dam breaking with lattice Boltzmann method (LBM). LBM considers a typical volume element of fluid to be composed of a collection of particles that represented by a particle velocity distribution function for each fluid component at each grid point. We use the modified Lattice Boltzmann Method for incompressible fluid. This paper will represent detailed information on single phase flow which considers only the water instead of both air and water. Interface treatment and conservation of mass are the most important things in simulating free surface where the Interface is treated by mass exchange with the water region. We consider the surface tension on the interface and also bounce back boundary condition for the treatment of solid obstacles. We will compare the results of the simulation with some methods and experimental results.

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Self-assembly of Dumbbell-shaped Rod Amphiphiles Based on Dodeca-p-phenylene

  • Huang, Zhegang;Liu, Libin;Lee, Eun-Ji;Lee, Myong-Soo
    • Bulletin of the Korean Chemical Society
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    • 제29권8호
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    • pp.1485-1490
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    • 2008
  • Dumbbell-shaped aromatic amphiphilic molecules consisting of a dodeca-p-phenylene as a rigid segment and oligoether dendrons as a flexible chains were synthesized, characterized, and their aggregation behavior was investigated in the bulk and at the air-water interface. In contrast to the molecule 2 which shows a nematic liquid crystalline state, molecule 1 based on shorter dendritic chains was observed to self-assemble into a 3-D primitive orthorhombic supercrystal. And molecule 1 at the air-water interface was observed to reorganize from circular plates to ring structures by lateral compressions.

DLPC LB박막의 전기특성에 관한 연구 (A Study on the Electrical Properties of DLPC LB films)

  • 조수영;이경섭;오재한;이우선;최충석
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1998년도 추계학술대회 논문집
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    • pp.97-100
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    • 1998
  • We studied on the ultra thin L-${\alpha}$-DLPC by LB method. The $\pi$-A isotherm of the L-${\alpha}$-DLPC was measured at the air-water interface varying with the compressing speed and amounts of solutions for spreading. The molecular arrangement of deposited films were evaluated by measuring the absorption with the UVspectrometer. And we made structures of metal(Au)/L-${\alpha}$-DLPC/Metal(Au) and examined electron through L-${\alpha}$-DLPC LB films by means of current-voltage(I-V) measurement.

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공기와 물이 형성하는 계면에서 발생하는 유기적으로 기능화된 은 나노 입자들의 2차원 조립 (Two-dimensional Assembly of Organically Functionalized Ag Nanoparticles at Air-water Interface)

  • 정성욱
    • 공업화학
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    • 제28권1호
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    • pp.125-131
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    • 2017
  • 본 연구에서는 유기적으로 기능화된 은 나노 입자들은 공기와 물이 형성하는 계면에서 자발적 조립 과정을 통해 새로운 2차원 상부 구조들(superstructures)을 생성하는 것을 발견하였다. 상부 구조의 분석은 금속 나노 입자의 심형과 입자계면에 결합된 유기 분자의 크기를 바꿈으로써 입자 간 특징적 상호 작용(characteristic inter-particle interaction)을 조절할 수 있고 이들 사이의 미묘한 상호 작용(subtle interplay)을 통해 은 나노 입자의 2차원 조립이 발생함을 시사한다. 본 연구를 통해 발견한 새로운 구조들은 기능성 나노 소재, 촉매 및 소자 응용 분야에 매우 중요한 잠재적 용도가 있을 것이라 사료된다.

Simultaneous Control of Au Nanotube Lengths and Pore Sizes with a Single Kind of Polycarbonate Membrane via Interfacial Deposition at the Air/Water Interface

  • Pyo, Myoung-Ho;Joo, Jung-Sook;Jung, Youn-Su
    • Bulletin of the Korean Chemical Society
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    • 제28권8호
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    • pp.1285-1288
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    • 2007
  • Au was electrolessly deposited on polycarbonate (PC) membranes (0.1 μm pores) at the air/water interface. It was found that the Au nanotube dimension can be controlled by adjusting the plating temperature and the solution composition. Interfacial deposition of Au at relatively low temperatures (4℃) produced long nanotubes, which run through the whole membrane thickness with small openings. Increase of plating temperatures resulted in the decrease of nanotube lengths and Au film thicknesses. It was also disclosed that the inside-diameter of Au nanotubes can be controlled with negligible variations in length by changing the composition of a plating solution.

Kuhn형 LB막 누적장치에서의 변위전류 측정 (Measurement of the displacement current using Kuhn-type LB film apparatus)

  • 송경호;박태곤;박근호;권영수;강도열
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1993년도 하계학술대회 논문집 B
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    • pp.1200-1202
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    • 1993
  • There are many methods to investigate the physical properties of monolayers formed at the air-water interface. Among them, the displacement current method is appropriate for the investigation of the dynamic behavior of monolayers. The measuring system of displacement current method was constructed at home-made Kuhn type LB deposition apparatus using aluminium plate electrode. The currents induced by the dynamic motion of molecules were measured when the molecules were pressed by barrier. To verify the measuring system, we used 4-octyl -4'-(5-carboxy-pentamethyleneoxy)-azobenzene molecules which has two remarkable variations of surface pressure of monolayer at the air-water interface. We can detect the two peaks of displacement currents which shows that the orientations of molecules are changed greatly at the state of these two remarkable changes of surface pressure.

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